59 



of straining and pressing is repeated ; the extracts obtained in this 

 way are mixed together and form the insecticide. A decoction of the 

 root and other parts of Bryonia alba (white bryony) can be used against 

 Aphids, etc. (one part by weight in three or four parts of water). 

 To prepare an extract of Coninm maculatum (hemlock), 100 parts by 

 weight of fresh leaves with flowers and small stalks are cut into small 

 pieces, mixed with five or six parts of water and ground in a mortar ; 

 the pulp obtained is then pressed out and again mixed with 15 parts of 

 water ; this is again ground and pressed out, the second liquid being 

 added to the first. Extracts of the tropical species of aloes are also 

 effective against various insects, as has been proved by experiment. 



ScHREiBER (A. F.). PaCTMTeJibHbie MHCeKTMCMflbl. [Vegetable insecti- 

 cides.]^ « CaAOBOAl>-)> [The Horticulturist], Rostov-on-Don, no. 12, 

 December 1915, pp. 903-912. 



The good results obtained by some insecticides of vegetable origin 

 [see also this Review, Ser. A, iii, pp. 340, 440, 441 and 486], such as a 

 decoction of tomato leaves and stalks against the caterpillars of 

 Pieris brassicae, are discussed. A decoction of leaves of Veratrum 

 album or V. nigrum against pests of market-gardens is the only remedy 

 used by the peasants in Transbaikal. Decoctions of Datura stramonium. 

 Petunia, Hyoscyamus niger, H. albus, H. major, Euphorbia biglandulosa 

 and E. dendroides are all recommended by Sprenger in "Die Gartenwelt" 

 (1912). The author describes his own experiments with extracts of 

 aloes, henbane {Hyoscyamus niger) and wormwood {Artemisia 

 absinthium) in 1915. The extract of aloes is sold ready-made, but 

 may be prepared by extracting the aloes in boiling water and adding 

 molasses to make it adhesive. Spraying is carried out early in the 

 morning, after the disappearance of dew, and again in the evening at 

 sunset. Henbane was cut into pieces while in flower, dried and boiled 

 in water till nearly all the water had evaporated ; the decoction 

 remaining was then strained through gauze, and for use, 1 lb. of the 

 extract and 1 lb. of soft soap are dissolved in about six gallons of 

 water. The decoction of wormwood was prepared in the same way, 

 1 lb. of it with 1| lb. of soft soap being dissolved in about four 

 gallons of water. Cabbage, salad-plants, turnips, bird-cherries, birch 

 trees, etc., were sprayed against Barathra {Mamestra) brassicae, 

 Plutella maculipennis {cruciferarum), Phyllotreta sp., and Aphis sp. 

 The best results were obtained with the aloes against all these pests ; 

 wormwood had little effect on Phyllotreta, and the extract of henbane 

 was effective only against Aphids. Extracts of tomatoes and hellebore 

 were very eSective against Aphids and various other market-garden 

 pests, such as B. brassicae, Plutella maculipennis, Pieris napi, 

 P. brassicae, P. rapae, and Phyllotreta. In order to prepare these 

 extracts, the plants must be dried, cut into pieces, closely packed in a 

 container and boiled in water, stirring and crushing the contents from 

 time to time. After five or six hours, when all the water will have 

 evaporated, the decoction is strained through gauze. It can be kept a 

 long time in bottles which are well corked ; for use, 1 lb. is dissolved 

 in about six gallons of water ; spraying should be done on sunny days 

 and repeated after rain. 



{C238) b2 



